Search Publications
The Coronal Mass Ejection of 1998 April 20: Direct Imaging at Radio Wavelengths
Pick, M.; Kerdraon, A.; Vourlidas, A. +2 more
We observed the fast coronal mass ejection (CME) of 1998 April 20 with the radioheliograph at Nançay, France, between 164 and 432 MHz. Spectroscopic data were obtained between 40 and 800 MHz by the spectrometer at Tremsdorf, Germany, and between 20 kHz and 14 MHz with the WAVES instrument on board the Wind spacecraft. Energetic particle data were …
Evolution of Two EIT/Hα Moreton Waves
Vršnak, B.; Hanslmeier, A.; Aurass, H. +1 more
Since the discovery of EIT waves, questions have remained about the driver of these disturbances and their association with the chromospheric Moreton waves. In order to resolve some of these issues, two flare-associated transient events (1997 November 3 and 1998 May 2) observed simultaneously in Hα and EIT are analyzed. The cospatiality of Moreton…
Coronal Mass Ejections Associated with Impulsive Solar Energetic Particle Events
Kahler, S. W.; Reames, D. V.; Sheeley, N. R., Jr.
An impulsive solar energetic particle (SEP) event observed on the Wind spacecraft on 2000 May 1 was associated with an impulsive solar active region M1 X-ray flare. The timing and position of a fast (v=960 km s-1), narrow CME observed in the LASCO coronagraph on SOHO make clear the connection between the CME and the flare and SEP event.…
Chandra X-Ray Observations of Pictor A: High-Energy Cosmic Rays in a Radio Galaxy
Young, A. J.; Wilson, A. S.; Shopbell, P. L.
We report X-ray observations of the nearby, powerful radio galaxy Pictor A with the Chandra Observatory and optical and near-UV observations of its western radio hot spot with the Hubble Space Telescope. X-ray emission is detected from the nucleus, a 1.9‧ (110 kpc) long jet to the west of the nucleus, the western radio hot spot some 4.2‧ (240 kpc)…
Material Outflows from Coronal Intensity ``Dimming Regions'' during Coronal Mass Ejection Onset
Harra, Louise K.; Sterling, Alphonse C.
One signature of expulsion of coronal mass ejections (CMEs) from the solar corona is the appearance of transient intensity dimmings in coronal images. These dimmings have generally been assumed to be due to discharge of CME material from the corona, and thus the ``dimming regions'' are thought of as an important signature of the sources of CMEs. W…
Dusty Debris around Solar-Type Stars: Temporal Disk Evolution
Zuckerman, B.; Silverstone, M. D.; Becklin, E. E. +2 more
Using ISO-ISOPHOT, we carried out a survey of almost 150 stars to search for evidence of emission from dust orbiting young main-sequence stars, both in clusters and isolated systems. Over half of the detections are new examples of dusty stellar systems and demonstrate that such dust can be detected around numerous stars older than a few times 10
The Origin of C IV Absorption Systems at Redshifts z < 1: Discovery of Extended C IV Envelopes around Galaxies
Chen, Hsiao-Wen; Lanzetta, Kenneth M.; Webb, John K.
We report the discovery of extended C IV gaseous envelopes around galaxies of a wide range of luminosity and morphological type. First, we show that C IV absorption systems are strongly clustered around galaxies on velocity scales of v<~250 km s-1 and impact parameter scales of ρ<~100 h-1 kpc, but not on larger velocity…
Complete and Simultaneous Spectral Observations of the Black Hole X-Ray Nova XTE J1118+480
Garnavich, P. M.; Groot, P. J.; Miller, J. M. +13 more
The X-ray nova XTE J1118+480 suffers minimal extinction (b=62deg) and therefore represents an outstanding opportunity for multiwavelength studies. Hynes et al. conducted the first such study, which was centered on 2000 April 8 using UKIRT, EUVE, HST, and RXTE. On 2000 April 18, the Chandra X-Ray Observatory obtained data coincident with…
A Serendipitous Galaxy Cluster Survey with XMM: Expected Catalog Properties and Scientific Applications
Romer, A. Kathy; Viana, Pedro T. P.; Liddle, Andrew R. +1 more
This paper describes a serendipitous galaxy cluster survey that we plan to conduct with the XMM X-ray satellite. We have modeled the expected properties of such a survey for three different cosmological models, using an extended Press-Schechter formalism combined with a detailed characterization of the expected capabilities of the European Photon …
Solar Neutrino Emission Deduced from a Seismic Model
Kosovichev, A. G.; Christensen-Dalsgaard, J.; García, R. A. +10 more
Three helioseismic instruments on the Solar and Heliospheric Observatory have observed the Sun almost continuously since early 1996. This has led to detailed study of the biases induced by the instruments that measure intensity or Doppler velocity variation. Photospheric turbulence hardly influences the tiny signature of conditions in the energy-g…